refactors psscanner

internal/psscanner/proclist.go

@@ -0,0 +1,103 @@
+package psscanner
+
+import (
+	"fmt"
+	"io/ioutil"
+	"os"
+	"strconv"
+	"strings"
+)
+
+var procDirReader = func() ([]os.FileInfo, error) {
+	return ioutil.ReadDir("/proc")
+}
+
+var procStatusReader = func(pid int) ([]byte, error) {
+	statPath := fmt.Sprintf("/proc/%d/status", pid)
+	return ioutil.ReadFile(statPath)
+}
+
+var cmdLineReader = func(pid int) ([]byte, error) {
+	cmdPath := fmt.Sprintf("/proc/%d/cmdline", pid)
+	return ioutil.ReadFile(cmdPath)
+}
+
+type procList map[int]string
+
+func (pl procList) refresh(eventCh chan string) error {
+	pids, err := getPIDs()
+	if err != nil {
+		return err
+	}
+
+	for i := len(pids) - 1; i >= 0; i-- {
+		pid := pids[i]
+		_, ok := pl[pid]
+		if !ok {
+			cmd, err := getCmd(pid)
+			if err != nil {
+				cmd = "???" // process probably terminated
+			}
+			uid, err := getUID(pid)
+			if err != nil {
+				uid = "???"
+			}
+			eventCh <- fmt.Sprintf("CMD: UID=%-4s PID=%-6d | %s", uid, pid, cmd)
+			// if print {
+			// 	log.Printf("\x1b[31;1mCMD: UID=%-4s PID=%-6d | %s\x1b[0m\n", uid, pid, cmd)
+			// }
+			pl[pid] = cmd
+		}
+	}
+
+	return nil
+}
+
+func getPIDs() ([]int, error) {
+	proc, err := procDirReader()
+	if err != nil {
+		return nil, fmt.Errorf("opening proc dir: %v", err)
+	}
+
+	pids := make([]int, 0)
+	for _, f := range proc {
+		if f.IsDir() {
+			name := f.Name()
+			pid, err := strconv.Atoi(name)
+			if err != nil {
+				continue // not a pid
+			}
+			pids = append(pids, pid)
+		}
+	}
+	return pids, nil
+}
+
+func getCmd(pid int) (string, error) {
+	cmd, err := cmdLineReader(pid)
+	if err != nil {
+		return "", err
+	}
+	for i := 0; i < len(cmd); i++ {
+		if cmd[i] == 0 {
+			cmd[i] = 32
+		}
+	}
+	return string(cmd), nil
+}
+
+func getUID(pid int) (string, error) {
+	stat, err := procStatusReader(pid)
+	if err != nil {
+		return "", err
+	}
+	lines := strings.Split(string(stat), "\n")
+	if len(lines) < 9 {
+		return "", fmt.Errorf("no uid information")
+	}
+	uidL := strings.Split(lines[8], "\t")
+	if len(uidL) < 2 {
+		return "", fmt.Errorf("uid line read incomplete")
+	}
+	return uidL[1], nil
+}